and selective Pd‐catalyzed cross‐coupling of aromatic boronic acids with vinyl‐imidazoles is disclosed. Unlike most cross‐coupling reactions, this method operates well in absence of bases avoiding the formation of by‐products. The reactivity is highly enhanced by the presence of nitrogen‐based ligands, in particular bathocuproine. The method involves MnO2 as oxidant for the oxidation Pd (0)→Pd (II), a
Stille Cross-Coupling for the Functionalization of the Imidazole Backbone: Revisit, Improvement, and Applications of the Method
作者:Alexander H. Sandtorv、Karl Wilhelm Törnroos、Hans-René Bjørsvik
DOI:10.1002/ejoc.201500328
日期:2015.6
We have revisited the Stille coupling reaction for the functionalization of the imidazolebackbone. In this context CuI was exploited as a co-catalyst, which resulted in significantly improved yields of target coupling products. Furthermore, a systematic investigation of the effect of the auxiliary group on the N-1-ring atom was performed. When mono-coupling is desired, the Tosyl (Tos) group is superior
Synthesis and Diels−Alder Reactions of 4-Vinylimidazoles
作者:Carl J. Lovely、Hongwang Du、H. V. Rasika Dias
DOI:10.1021/ol015687m
日期:2001.5.1
[GRAPHICS]The synthesis of several 4-vinylimidazoles via Stille cross-coupling reactions of the corresponding protected 4-iodoimidazoles with tributylvinylstannane is described, These heterocyclic dienes are shown to be effective partners in the Diels-Alder reaction, providing adducts in good yield acid exhibiting useful levels of isomer selectivity and stereoselectivity (endo/exo).